Implemented the "ref" namespace to get configuration tree references. BUGS: - Tests should be done more thoroughly and extensively - Interaction of tree references and variable substitution should be tested more properly - Documentation is missing yet

# -*- coding: utf-8; mode: yaml; indent-tabs-mode: nil; -*-
#
# Part of deletion check
#
%YAML 1.1
---

db:
  user:
    name: '{{::DEL::}}'

test:
  Str: '{{::DEL::}}'


to-be-deleted-but-reassigned: 'the last value'